3 Americans freed by North Korea ahead of Donald Trump-Kim Jong-un summit

North Korea released three American prisoners and handed them over to US Secretary of State Mike Pompeo on Wednesday, clearing a major obstacle to an unprecedented summit between President Donald Trump and North Korean leader Kim Jong-un.

The men, who were freed after Pompeo met Kim, were on their way home aboard the chief US diplomat's plane, and Trump said he would greet them when they arrived at Andrews Air Force Base outside Washington on Thursday morning.

"We would like to express our deep appreciation to the United States government, President Trump, Secretary Pompeo, and the people of the United States for bringing us home," the three said in a statement released by the State Department as their plane stopped over in Alaska.

"We thank God, and all our families and friends who prayed for us and for our return. God Bless America, the greatest nation in the world."

The release, praised by the White House as a "gesture of goodwill," appeared to signal an effort by Kim to set a more favourable tone for the summit and followed his recent pledge to suspend missile tests and shut a nuclear bomb test site.

While Kim is giving up the last of his American detainees, whom North Korea has often used as bargaining chips, their return could also be aimed at pressuring Trump to make concessions as he tries to get Pyongyang to abandon its nuclear arsenal, something it has not signalled a willingness to do.

The release gave Trump a chance to tout a diplomatic achievement just a day after his decision to pull out of the Iran nuclear deal drew heavy criticism from European allies and others.

"I am pleased to inform you that Secretary of State Mike Pompeo is in the air and on his way back from North Korea with the 3 wonderful gentlemen that everyone is looking so forward to meeting. They seem to be in good health," Trump wrote on Twitter.

"I appreciate Kim Jong Un doing this and allowing them to go," Trump told reporters at the White House.

Kim's handover of the Americans was in response to an "official suggestion" from Trump, the North Korean state news agency KCNA said in its account of the talks with Pompeo. It was their second encounter in less than six weeks to prepare the first-ever meeting between sitting US and North Korean leaders.

Trump said agreement had been reached on a date and venue for the summit and details would be announced within three days. He ruled out the heavily fortified demilitarized zone between North and South Korea, increasing the possibility the meeting could take place in Singapore, which he previously said was under consideration.

FIRST STEP

Kim said the summit would be an "excellent first step" towards an improved situation on the Korean peninsula, according to KCNA. Though tensions have eased recently, it was just months ago that fears of war were running high in the region.

The family of Tony Kim, one of the freed prisoners, said in a statement: "We are very grateful for the release of our husband and father, Tony Kim, and the other two American detainees."The fate of the three Korean-Americans had been among a number of delicate issues in the run-up to summit, which is being planned for late May or early June.

As Pompeo returned to his Pyongyang hotel from a 90-minute meeting with Kim, the secretary of state crossed his fingers when asked by reporters if there was good news about the prisoners.

A North Korean official came to the hotel shortly afterwards to inform Pompeo that Kim had granted them "amnesty," according to a senior US official present for the exchange.

"You should make care that they do not make the same mistakes again," the North Korean official was quoted as saying. "This was a hard decision."The three, who walked without assistance to Pompeo's plane and were seated near medical personnel, were in the air less than an hour after leaving custody.

"They were happy to be with us on this plane, to be sure," Pompeo told reporters during the flight.

They are Korean-American missionary Kim Dong-chul, detained in 2015; Kim Sang-duk, also known as Tony Kim, who spent a month teaching at the foreign-funded Pyongyang University of Science and Technology (PUST) before he was arrested in 2017; and Kim Hak-song, who also taught at PUST and was detained last year.

North Korean state media says they were arrested either for subversion or "hostile acts" against the government.

'VERY PRODUCTIVE'

Speaking to reporters, Pompeo said his meetings in Pyongyang were "very productive." The two sides agreed to meet again to finalise details of the summit, a US official said.

KCNA said Kim and Pompeo reached a "satisfactory consensus" on the issues they discussed, but provided no specifics.

U.S. Defense Secretary Jim Mattis said that while there was "reason for some optimism" about the summit, the US troop presence in South Korea would not be part of initial negotiations.

There was also no sign that Pompeo's visit had cleared up the question of whether North Korea would be willing to bargain away nuclear missiles that might threaten the United States.Trump has credited his "maximum pressure" campaign for drawing North Korea to the table and has vowed to keep sanctions in place until Pyongyang takes concrete steps to denuclearize.

But former spy chief Kim Yong Chul, director of North Korea's United Front Department, said in a toast to Pompeo over lunch in Pyongyang: "We have perfected our nuclear capability. It is our policy to concentrate all efforts into economic progress ... This is not the result of sanctions that have been imposed from outside."

Daniel Russel, until recently the most senior US diplomat for Asia, said the prisoner release would reduce tensions, but was not a sign that peace was at hand.

"We should hold off on awarding ourselves Nobel prizes. North Korea is stating clearly that what is on the table is merely tension reduction and possible ultimate global arms reduction. It is not talking about eliminating its own nuclear programme."